Pin-tumbler lock



F. W. SCHROEDER.

PIN TUMBLER LOCK.

APPLICATION FILED MAY 24, 1920.

Patented Dec. 12, 1922.

Fatented Bee, 1%, i922.

FREDERICK WILLIAIH SCHROEDER, OF LONDON, ENGLAND.

Pm-T'UMBLER LUCK.

application filed ma 1929. Serial no. seas/e.

(GEAHTED UHIDER '1 PBGVISIOIW THE ACT OF MARCH 3, 1921, til- STAT. 1., 1313.)

To all whom it may conc rn:

Be it known that I, FR DERICK WILLIAM SCHROEDER, a subject of'the King of Great.

Britain, residing 1n London, England, have invented certain new. and useful Improvements in Pin-Tumbler Looks (for whrchT have filed an application in Great Britain Nov. 25, 1916, Patent No. 139,003), of which the following is a specificatmn.

The present invention relates to pin tumbler locks and to ke s used in connection therewith, such locks eing of the kind that I consists of an outer barrel and an inner rotatable lock barrel, the two-barrels being locked together, except-when free to be unlocked b the operation of a key, b means of tumb er or looking pins divide transversely into two parts, the key for operating the tumblers being of the well-known 2o flat or non-tubular type, which has grooves on its sides, abevelled end and is provided along its two longitudinal edges wlth sets of notches and projections or wards for actuating the tumblers, which latter are forced by the bevelled end of the key along transverse or upright holes in the barrels on the key being inserted in a key slot in the rotatable lock barrel.

The invention consists in improvements so both in the lock and key. According to this invention, the keys for operating tumbler locks of the kind above alluded to have longitudinally disposed grooves formed along the crowns of the rojections on the longitudinal edges, in order that the apices of the customary pointed terminal parts of the movable tumbler pins will not be engaged or be rasped by the key projections as thekeys are inserted in or withdrawn to from the lock barrels. The keys may, more over, be provided with notches and projections along both of their longitudinal edges, so formed and arranged that a key will be ,capable of operating two difi erent looks fitted with similar lock barrels. An-

other improvement consists. inv forming a key with a single groove on each of its sides for a purpose hereinafter referred to.

The improvements will be described with reference to the accompanying drawing in which Fig. 1 is a longitudinal section of the lock with the key inserted and the tumblers "or locking pins in raised or in operative position wherein the lock barrel is free to be turned within the. outer barrel; F g. 2 is a cross section on 2-2 in Fig.1; Fig. 3 is an end'elevation of the lock with the key removed; Fig. 4: is an end view of one form of the lock barrel; Fig. 5 is an end view of a modified form of the lock barrel; Figs. 6 and 7 are respectively side and end elevations of a look similar to the lock illustrated in Figs. 1 to 3, but having the modified forms of lock barrel shown in Fig. 5, Fig.6 being partly in section, and Fig. 8 is a perspective view of a key formed according to this'invention. In the several figures, corresponding parts are indicated by corresponding letters.

In the drawing a is the outer barrel, 6 the inner barrel, and 0 is the key for operating the lock. The tumblers consist of a plurahty of members and comprise the lock pins d and plungers d which are urged downwardly or transversely of the outer barrel by springs e. The tumblers and their springs e are retained by any suitable means in theholes provided for their reception Within the barrels, for instance as has been previously suggested by the help of the curved plate'z' forced into dovetailed groovesa in the to of the barrel 0:. The inward movement 0 the tumblers when the key is withdrawn from the keyway or slot 6 is limited by their lower terminal portions engaging with the lateral parts 6 of the key slot, which parts are arranged to fit grooves formed as explained below, on the two sides ofthe key.

- The lock barrel may be formed as shown in Fig. 4 that is to say from a piece of metal that is pressed or stamped and notched along one edge and then bent or pressed to the proper shape, the key slot being left open at its lower or outer end. The lock barrel may, however, be formed as shown in Fig. 5 where the key slot is clowd at the bottom.

' The lock barrel 6 is secured in place within the outer barrel a in the usual manner by means of its front flanges b and the cap f fixed to the .lock barrel by the screw 9.

In the cap is fitted the customer latch bar or mem er k that is controlled in its operations by the movements of the lock barrel.

. As regards the improvements in the lock itself in order to render it more difiicult to pick'the barrel of the lock, it is provided with a rib or fixed pin 6 which projects into the key slot and co-operates with a groove provided on the ward edge of the key as hereinafter described. Such ribvprojects but only to such an extent as will permit all the wards c of the keys to pass freely under-it. This is rendered possible by the provision of a longitudinal groovealong the upper edge ofthe keyas herein-v after referred to; This fixed rib orpin prevents access to the movable pins 01' in rear thereof and thus prevents the lock bein picked.-

hen the lock barrel is formed 'as shown in Figs. 1 to 4, it is provided with only one rib 6*, but when it 1s constructed asindicated in Figs. 5 to 7 there will be an additional rib b projecting into the bottom of the key slot.

.As regards theimprovements' in the key itself; this may be provided with wards and notches along both of its longitudinal edges, as is the case with keys used with certain known locks of the type referred to and having two diametrically opposite rows of locking pins, but according to this invention the wards and notches on one edge are respectively opposite the wards and notches on the other edge of the key, which enables it when inserted in one position of the lock barrel of-one lock, such as that on the main door of a building to operate or shift the co-operating tumbler pins, and when inserted in the reverse position in a precisely similar lock barrel of another look such as the private door of the owners flat, or set of apartments in the building to operate the pins co-operating with that barrel, no change in the form of barrel being necessary. Thekey shown in the drawing has on one'edge-wards 0 opposite wards 0 on the other edge, while the notches c and 0 are also oppositely disposed.

In order to prevent such a key, when used with a lock having the key slot in the lock barrel open at the bottom as in Figs. 1 to 4, being turned more than half a turn which would permit the pin tumblers to enter the notches on the wrong edge of the key, the cylinder of the lock barrel is provided with a suitable slot or slots 6 with which engages a fixed pin j which is fixed in the outer barrel a, so that the rotation of the cylinder more than a certain distance is effectually prevented.

Pin tumbler locks of the kind referred to as at present constructed are liable to get out of order by the'wearing away of the end of the pins due to the constant passage of such pins over the wards of the key.

This disadvantage is overcome by makin a further improvement in the key. Such 1mprovement consists in forming one or both ward edges of the key with a longitudinal groove of such sha e that the sides of the pointed or bevelle terminal parts of the movable pins (13. on the sides of this groove whereas the actual apices or points of the said parts do not themselves touch the key when passing over or along the set of wards, as shown in broken lines in 5 Fig. 2 until each terminal part drops into its own particular notch when the key has been pushed home through the key slot, sothat'the tumblers and notches become properly aligned.

Another improvement according to this invention consists in forming the key with a single groove 0 on each of its two sides, which enables a key,to be stamped, whereas in keys hitherto employed with locks of the "kind above referred to, there have been a number of grooves on each side which have of necessity been cut or milled.

Having thus described the nature of the said invention and the best means I know of carrying the same into practical effect,

'claimz- 1. In combination a pin tumbler lock having a barrel provided with a key slot,

tumbler pins projecting into said key slot, a key adapted to enter said slot and having wards thereon, said pins having lateral portions engageable with said wards while said key is being pushed into operative position and having terminal portions engageable with said wards only when said key is in operative position.

2. A pin tumbler lock and key combination as claimedin claim 1, the crowns of the projections or wards of the key grooved in a direction longitudinal of the key, the angle subtended by the two opposite sides of the grooves being less than the angle at the apex of the terminal bler locking pin.

3. In a pin tumbler lock and key combination as in claim 1, a projection on the wall of the key slot, and a key having on each of its sides a single groove shaped to correspond with said projections and adapted, when the key is inserted in the key slot of the lock barrel,to engage with said projection.

4. In a tumblerlock and key combination as set forth in claim 1, a lock barrel provided with a longitudinally disposed rib arranged to project into the key slot thereof,

- substantially as and for the purpose de- FREDERICK WILLIAM SCHIIOIEDElRa part of each tum- 

